A = [-4.12 -17.4 -30.8 -60; 1 0 0 0; 0 1 0 0; 0 0 1 0]; B = [1; 0; 0; 0]; C = [4 8.4 30.78 60]; D = 0; sys = ss(A, B, C, D); [num,den] = tfdata(sys, 'v') [z,p,k] = zpkdata(sys,'v')